Method and apparatus for video deinterlacing and format conversion

• US 20050134730A1
• Filed: 12/23/2003
• Published: 06/23/2005
• Est. Priority Date: 12/23/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Linzer, Elliot N., Winger, Lowell L., Wells, Aaron G., Cote, Guy, Booth, Simon, Jia, Yunwei
• Granted Patent: US 7,345,708 B2
• Time in Patent Office: Days
• US Class Current: 348/448
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229

Abstract

A method for deinterlacing a picture is disclosed. The method generally includes the steps of (A) determining a protection condition by performing a static check on the picture in a region around a location interlaced with a first field of the picture, (B) calculating an interpolated sample at the location by temporal averaging the first field with a second field in response to the protection condition indicating significant vertical activity and (C) calculating the interpolated sample at the location by spatial filtering the first field in response to the protection condition indicating insignificant vertical activity.

Claims

1. A method for deinterlacing a picture, comprising the steps of:

(A) determining a protection condition by performing a static check on said picture in a region around a location interlaced with a first field of said picture;

(B) calculating an interpolated sample at said location by temporal averaging said first field with a second field in response to said protection condition indicating significant vertical activity; and

(C) calculating said interpolated sample at said location by spatial filtering said first field in response to said protection condition indicating insignificant vertical activity.

2. The method according to claim 1, further comprising the step of:

evaluating said region for a stationary horizontal edge in said picture prior to calculating said interpolated sample.

3. The method according to claim 2, further comprising the step of:

calculating said interpolated sample at said location by step (B) in response to evaluating said region indicating that said location is on a side of said stationary horizontal edge having a static content.

4. The method according to claim 1, wherein said static checking operates on said first field and a third field having a same parity.

5. A method for deinterlacing a picture, comprising the steps of:

(A) generating a plurality of scores by searching along a plurality of angles for an edge in said picture proximate a location interlaced with a field of said picture;

(B) penalizing said scores as a function of said angles; and

(C) calculating an interpolated sample at said location by directional filtering said first field along a best of said angles corresponding to a best of said scores after said penalizing.

6. The method according to claim 5, wherein a penalty value added to said scores in step (B) increases as said angles approach horizontal.

7. The method according to claim 6, further comprising the step of calculating said interpolated sample at said location by vertical filtering said first field in response to a threshold exceeding said best value including said penalty value.

8. The method according to claim 5, further comprising a step of:

reducing a bit-depth of said field prior to generating said scores.

9. A method for deinterlacing a picture, comprising the steps of:

(A) generating a plurality of first samples to deinterlace a field of said picture;

(B) marking said first samples having at least one characteristic above a confidence level;

(C) generating a plurality of second samples based on said characteristics of said first samples that have been marked; and

(D) replacing each of said first samples not marked with a corresponding one of said second samples.

10. The method according to claim 9, further comprising the step of:

marking said second samples having at least one of said characteristics above said confidence level.

11. The method according to claim 10, further comprising the steps of:

generating a plurality of third samples based on said characteristics of said second samples that have been marked; and

replacing each of said second samples not marked with a corresponding one of said third samples.

12. The method according to claim 11, wherein said at least one characteristic comprises belonging to an edge in said picture.

13. A method for deinterlacing a picture, comprising the steps of:

(A) generating a plurality of scores for a plurality of angles through a location interlaced with a field of said picture;

(B) comparing a confidence level for a best of said scores with a threshold level; and

(C) generating an interpolated sample at said location by directional filtering said field along a best of said angles corresponding to said best score in response to said confidence level for said best score exceeding said threshold level.

14. The method according to claim 13, further comprising the step of:

generating said interpolated sample at said location by vertical filtering said field in response to said threshold level exceeding said confidence level for said best score.

15. The method according to claim 13, further comprising the step of:

generating said confidence level for said best score inversely proportional to said best score.

16. The method according to claim 15, wherein generating said confidence level comprises the sub-step of:

summing a plurality of inverses of said scores.

17. A method for deinterlacing a picture, comprising the steps of:

(A) generating a plurality of primary scores by searching along a plurality of line segments in a plurality of sets for an edge in said picture proximate a location interlaced with a field of said picture, said line segments in each of said sets being parallel to (i) each other and (ii) a corresponding one of a plurality of primary angles;

(B) generating a plurality of average scores by averaging said primary scores for said parallel line segments in each of said sets;

(C) generating a plurality of neighbor scores by searching for said edge along a plurality of neighbor angles proximate a particular angle of said primary angles corresponding to a particular score of said average scores having a best value; and

(D) identifying a best score from a group of scores consisting of said particular score and said neighbor scores to use in generating an interpolated sample at said location.

18. The method according to claim 17, further comprising the step of:

calculating said interpolated value at said location by directional filtering said field along a best angle corresponding to said best score, said best angle belonging to a group of angles consisting of said particular angle and said neighbor angles.

19. The method according to claim 17, wherein said neighbor angles consist of two angles, one on each side of said particular angle.

20. The method according to claim 17, wherein said primary angles are unevenly separated from each other.